1. Field of the Invention
The present invention relates to the field of displaying technology, and in particular to an array substrate structure and a manufacturing method thereof.
2. The Related Arts
A touch screen allows a user to operate a host device by touching a symbol and text displayed on a display screen of a computer. This allows operations to be carried out without of keyboards and mice and provides man-machine interfacing in a more straightforward manner. The major applications are information inquiry in public places, guidance of office operations, electronic games, songs and dishes ordering, multimedia teaching/learning, and advanced sales of airplane and train tickets. Products are generally classified in three categories, including capacitive touch screens, resistive touch screens, and surface acoustic wave touch screens.
An array substrate is an important component of a touch screen panel.
Referring to FIG. 1, a cross-sectional view is given to illustrate a conventional array substrate structure for use with a touch screen panel. The array substrate comprises a base plate 100, a buffer layer 200 formed on the base plate 100, a semiconductor layer 300 formed on the buffer layer 200, a gate insulation layer 410 formed on the buffer layer 200 and the semiconductor layer 300, an interlayer dielectric layer 420 formed on the gate insulation layer 410, a source/drain terminal 500 formed on the interlayer dielectric layer 420, a planarization layer 600 formed on the source/drain terminal 500 and the interlayer dielectric layer 420, a second metal layer 700 formed on the planarization layer 600, a first insulation layer 810 formed on the second metal layer 700 and the planarization layer 600, a common electrode 910 formed on the first insulation layer 810, a second insulation layer 820 formed on the common electrode 910 and the first insulation layer 810, and a pixel electrode 920 formed on the second insulation layer 820.
A first via 510 is formed in the gate insulation layer 410 and the interlayer dielectric layer 420 to correspond to the semiconductor layer 300. A second via 520 is formed in the first insulation layer 810 to correspond to the second metal layer 700. A third via 530 is formed in the planarization layer 600, the first insulation layer 810, and the second insulation layer 820 to correspond to the source/drain terminal 500.
The semiconductor layer 300 comprises a source/drain contact zone 310. The source/drain terminal 500 is set in engagement with the source/drain contact zone 310 of the semiconductor layer 300 through the first via 510. The common electrode 910 is set in engagement with the second metal layer 700 through the second via 520. The pixel electrode 920 is set in engagement with the source/drain terminal 500 through the third via 530.
The second metal layer 700 is provided for connection with a touch sensing electrode.
Specifically, the second insulation layer 820 comprises a material of SiNx and the common electrode 910 comprises a material of ITO (Indium Tin Oxide).
Specifically, plasma enhanced chemical vapor deposition (PECVD) is used to form second insulation layer 820 (SiNx layer), of which the reaction is as follows:

in other words, SiH4, NH3, and N2 react under an effect of an electromagnetic field generated by radio frequency (RF) power to generate SiNx:H and H2. The H2 atmosphere generated by the reaction is reductive and may readily cause reduction of a surface layer of the common electrode 910. As shown in FIG. 2, a reduced ITO layer 912 is formed on the surface of the common electrode 910 and an ITO layer 914 is present under the reduced ITO layer. The reduced ITO layer 912 is poor in light transmittance so that the overall light transmittal of the common electrode 910 is lowered down thereby making the overall light transmittance of the touch screen panel reduced and thus affecting the displaying performance of a panel (such as brightness).
Thus, it is desired to provide an array substrate structure and a manufacturing method thereof to overcome the above problems.